Sodium Channel Voltage Gated Type I Beta (SCN1b)

Voltage-gated sodium channels are essential for the generation and propagation of action potentials in striated muscle and neuronal tissues. Biochemically, they consist of a large alpha subunit and 1 or 2 smaller beta subunits, such as SCN1B. The alpha subunit alone can exhibit all the functional attributes of a voltage-gated Na+ channel, but requires a beta-1 subunit for normal inactivation kinetics.The C-terminal half of the deduced 218-amino acid protein contains a transmembrane domain. Rat and human SCN1B share 98% amino acid identity. Northern blot analysis detected abundant expression of a 1.5-kb transcript in several human brain regions, including brainstem and cerebellum. Expression was also detected in human skeletal muscle and heart and in rat myoblasts, but not in human liver.